HBASE-28838 use CompletableFuture instead of fixed sleep during the …

hbase-server/src/main/java/org/apache/hadoop/hbase/master/HMaster.java

@@ -52,8 +52,8 @@
 import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
+import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
-import java.util.concurrent.Future;
 import java.util.concurrent.Semaphore;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
@@ -2403,6 +2403,8 @@ public void move(final byte[] encodedRegionName, byte[] destServerName) throws I
 
       TransitRegionStateProcedure proc =
         this.assignmentManager.createMoveRegionProcedure(rp.getRegionInfo(), rp.getDestination());
+      CompletableFuture<String> completableFuture = new CompletableFuture<>();
+      proc.setCompletableFuture(completableFuture);
       if (conf.getBoolean(WARMUP_BEFORE_MOVE, DEFAULT_WARMUP_BEFORE_MOVE)) {
         // Warmup the region on the destination before initiating the move.
         // A region server could reject the close request because it either does not
@@ -2412,11 +2414,10 @@ public void move(final byte[] encodedRegionName, byte[] destServerName) throws I
         warmUpRegion(rp.getDestination(), hri);
       }
       LOG.info(getClientIdAuditPrefix() + " move " + rp + ", running balancer");
-      Future<byte[]> future = ProcedureSyncWait.submitProcedure(this.procedureExecutor, proc);
+      ProcedureSyncWait.submitProcedure(this.procedureExecutor, proc);
       try {
         // Is this going to work? Will we throw exception on error?
-        // TODO: CompletableFuture rather than this stunted Future.
-        future.get();
+        completableFuture.get();
       } catch (InterruptedException | ExecutionException e) {
         throw new HBaseIOException(e);
       }

hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/TransitRegionStateProcedure.java

@@ -144,6 +144,8 @@ public class TransitRegionStateProcedure
 
   private CompletableFuture<Void> future;
 
+  private CompletableFuture<String> completableFuture;
+
   public TransitRegionStateProcedure() {
   }
 
@@ -747,4 +749,16 @@ public static TransitRegionStateProcedure move(MasterProcedureEnv env, RegionInf
     return setOwner(env, new TransitRegionStateProcedure(env, region, targetServer,
       targetServer == null, TransitionType.MOVE));
   }
+
+  @Override
+  protected void completionCleanup(MasterProcedureEnv env) {
+    if (null != completableFuture) {
+      completableFuture.complete("done");
+    }
+  }
+
+  public void setCompletableFuture(CompletableFuture<String> completableFuture) {
+    this.completableFuture = completableFuture;
+  }
+
 }